This project represents an ongoing collaborative effort, involving WHO and other national and international laboratories to coordinate the collection, evaluation and interpretation of normal genetic markers, in order to, study the cross-cultural patterns of genetic and extraneous factors as they relate to normative aging and to diseases with late onset. Specifically, the objectives of this study are: A) To study the distribution of DNA minisatellites, dermatoglyphics, lateral dominance and other genetic variables in BLSA participants and other control samples, as well as in patients with late onset diseases. B) To study the genetic segregation of these markers in families with late onset diseases, such as Alzheimer's disease, breast cancer, ALS and others, in an effort to establish genetic linkages and eventual identification of the factors responsible for these diseases and C) To study the cross cultural patterns of genetic and non genetic factors in an effort to better understand the process of normative aging.